Calcium–aluminum carbonate (Ca–Al–CO 3 ) sorbents for CO 2 sorption were hydrothermally prepared and tested at 750 _x0002_C by thermal gravimetric (TG) analysis and ﬁxed-bed reactor method. The Ca/Al molar ratios of the sorbents ranged from 1:1 to 30:1. As the Ca/Al molar ratio increased, the CO 2 sorption mass increased from 13.4 to 74.2 wt%. The capturing stability remained stable at 99% in TG analyzer and 76% in the reactor (10 cycles at 750 _x0002_C). The kinetic parameter, estimated by the kinetic control model, indicated that the model was consistent with the carbonation reaction of Ca–Al–CO 3 with CO 2 in the kinetically controlled reaction regime. The estimated activation energy (E a ) of CO 2 sorption was 53.6 kJ/mol, slightly less than the typical E a of CaO carbonation reactions above 600 _x0002_C in ﬁxed-bed reactors. This reduction may be partially attributed to the co-existence of Ca(OH) 2 and CaO nanoparticles in the synthetic Ca–Al–CO 3 sorbents.